8oo THE POPULAR SCIENCE MONTHLY. 



also of being less adapted to England than to the United States. 

 Besides, why is it that evergreens thrive better, and are more hardv, 

 in a cultivated state in Europe, and deciduous trees in this country ? 

 We know answers can be given by experienced observers to all these 

 questions, that are more or less comprehensive, but we believe also that, 

 when such answers come to be closely scanned, it will be found that 

 they do not entirely meet the case. How is it, otherwise, that the same 

 peculiarities in a minor degree are evident in the behavior of trees 

 growing within a few miles of each other ? One might understand 

 why the same plants act differently farther inland, but here in the 

 neighborhood of the coast it naturally strikes us as curious that on the 

 Hudson River some plants are hardier than on Long Island. 



There are more inexplicable facts than these. Mr. Hunnewell can 

 grow plants on his lawn that will hardly live through some winters, 

 even under the most favorable conditions, on any other spot about 

 Boston. 



Nor is this the strangest feature to be noticed in the behavior of 

 plants under apparently like influences of soil and climate. Plants a few 

 feet from each other, of the same species, will suffer in very different 

 degrees during many winters. Rhododendrons are a notable instance 

 of this. It is not simply that Rhododendron ponticum and its hybrids 

 are not as hardy as Rhododendron CatawMense, nor that the more of 

 the Catawbiense strain there is in a Ponticum hybrid, the hardier it is, 

 but it is that sometimes a Ponticum hybrid, usually entirely unreliable, 

 will pass the winter unscathed, when nearly the hardiest pure Cataw- 

 biense of the plantation will be killed. But our expert says, " One did 

 not ripen its wood as well as the other." Yes, but is it not also strange 

 that sometimes the one which finally died was the one that had ripened 

 its wood most thoroughly ? 



A few striking examples like these should be suflicient to illus- 

 trate the great difficulty that must always attend the determina- 

 tion of the relative hardiness of plants. Many more instances of the 

 same character might be readily selected, but it is not necessary. We 

 have simply endeavored to give sufficient data to warrant the general 

 statement that the varying and complex conditions of the environ- 

 ment of any given plant are difficult to understand or explain on the 

 basis of experience of another environment which, to a superficial ob- 

 server, may seem to be identical with the first. Our intention is not 

 to insist on any explanation of the facts adduced in regard to the 

 relative hardiness of plants, but only to show distinctly the difficulties 

 that must attend such explanations, and to point out that experience is 

 now being purchased too dearly, and that it is, moreover, not of a 

 sufficiently varied character. Hundreds and thousands of plants are 

 killed every year under very similar circumstances, and it seems evi- 

 dent that human intelligence should be sufficient to compass some 

 method of reducing this loss to a minimum. 



